Laminated glass



1931- w. c. MCDANIEL 1,818,235

LAMI NATED GLAS 5 Filed July 23, 1928 gwm'ntoz (.d/l/ara C. Mc Dan/e!(liter an 1.;

Patented Aug. 11, 1931 UNITED STATES PATENT OFFICE WILLARD C.

KoDANIEL, or TOLEDO,- onro. assrenoa 'ro ,LraBEY-ownn s-rom Grass comma.or TOLEDO, 01:10, a CORPORATION or 01:10

LAIINATED GLASS Application filed July as, 1928. Serial no. 294,802.

The resent invention relates to' means Figs. 4 and 5 are fragmentarysectional.

adapte for use in the production of laminated glass.

An important object of the invention s to a provide means whereby aplurality of laminations may be arranged 1n.-proper.,super1mposedrelationship and held against slippage while said laminations arepermanently bonded together.

Another object of the invention is to provide means for use in theproduction of laminated glass wherein the laminations arearranged insandwich form after which a sheet of compressible material is arrangedon each side of the sandwich, the sandwich and compressible sheets beingheld in proper relationship by means of stickers which are removed afterthe laminations have been permanently bonded together.

as A further object of the invention is to provide means designed toprevent slippaige between the laminations o a. sandwich uring thepressin thereof, the said means being applied to an used in connectionwith the sandw wich in a manner that the possibility of strains beingset up in the sheet due to the use of said means is reduced to aminimum.

Still another and important object of the invention is to provide suchmeans which as are adapted to be applied to the sandwich in a mannerthat the non-brittle lamination can flow without being unnecessarilyretarded, as far as the sticker is concerned.

Other objects and advantages of the invention will become more apparentduring the description when the accompanying course of the followintaken in connection wit drawings.

In the drawings forming a part'of this application and wherein likenumerals are employedto designate like parts throughout the same,

Fig. 1 is a perspective view showing a laminated sandwich with stickersin proper position. i

Fig. 2 is a vertical section through a sandwich illustrating the samesuitably assembled for pressing. I

Fig. 3 is a diagrammatic representation of a press, and

views of two different forms of commercial products. V

In the production of laminated glass two or more sheets of glass and oneor more sheets of non-brittle material are united to form a compositenon-shatterable sheet. There are numerous ways" in which laminated lasscan be processed, but in (practically all 0 the cases some form of liquior bonding medium is used. To obtain the bond between the lami-, nationsit is quite customary to use a sheetof cellulose composition material asthe nonbrittle membrane or portion of the laminated sheet, and to obtaina. bond between it and the glass sheetssome form of bondin medium orcement is used. Due to the iquid characteristics of the bonding medium,after the laminations have been placed in sandwich form there is atendency for the lamina- 1o tions to slip relative to each other duringthe pressing operation. It is quite important that this slippage beovercome as ordinarily the glass sheets are cut to the proper sizebefore the laminated sheet is produced because of the difficulties incutting laminated glass after it has been made.

When producing laminated glass in accordance with some processes due'tothe heat and other conditions, the non-brittle sheet is extruded orflowed from the edges of the sandwich, that is due to the pressure andother conditions the size of the non-brittle sheet is greater after thepressing than before. If the non-brittle sheet and lass used are of thesame size during the eginning of the operation it will be seen that whenthe sandwich or finished product is removed from the press that thenon-brittle sheet will be slightly larger. It is rather essential thatthe flowing of the non-brittle sheet from between the glass sheets beun-interrupted as far as anyexternal means is concerned. If

the flowing of the non-brittle sheetbe interrupted at various points thetendency toward the formation of strains in the laminated product takesplace.

Referring to Fig. 1 the numeral 10 designates a sandwich formed from twosheets of glass and asheet of non-brittle material, the 100 sheets ofglass, and non-brittle sheets have been properly processed such as bythe ap understood that any other suitable material corner as illustratecan be used such asfor instance rubber, asbestos, etc, instead 7 of theblotting paper above mentioned. After the cushion members 11 have beencut to size and one placed on each side of the sandwich 10 stickers 12are used to hold the sandwich and cushion means in osition.

The stickers 12 may be ordinary gummed paper. The term stickers is usedin this specification and the claims to mean broadly any adhesive memberused to prevent slippage between the ruminations. It is preferred thatthe stickers be applied in a manner to prevent relative movement orslippage between the various sheets comprising the laminated sandwich. Barranging one at each in Fig. 1, it has been found that the laminationswill be held againstrelative movement. Attention is directed to the factthat the stickers 12 adhere to the cushion members 11 instead of to thesurfaces of the glass sheets.

In those cases where the non-brittle material has a tendency to flowor-extrude from between the glass sheets I have found it very desirableto arrange the stickers at an angle in the manner illustrated so thatthere is substantially line contact only between the stickers and theedges of the glass sheets. As there is line contact only the non-brittlesheet can flow without being retarded exce t at the very line of contactbetween said stic ers and the edges of the laminated sandwich. Thisarrangement of the stickers is considered ver important as it reduces toa minimum t e retardation of the flowing of the non-brittle sheet andthus removes a cause for the introduction of strains within thelaminated product.

After the cushion members 11 have been associated with the sandwich 10as shown in Fig. 1 additional cushion means 13 are arran ed as shown inFi 2. In this particular instance three additional sheets ofcompressible materiai have been placed on each side of the sandwich andcompressible sheets 11. The number of additional compressible sheets orcushion members 13 required is dependent upon the thickness of eachsheet, pressures umd, etc., and althou h it is important that the sheets11 be of e same size as the sandwich 10, the members 13 can be the samesize or larger.

The numeral 14 desifiates preferably two metallic plates one of w ch isplaced on each side of the sandwich and in contact with the outermostsheets 13. The plates 14 are preferabl of thin flexible metal. Theentire assemb y shown in Fig. 2 may then be placed in a press designatedin its entiret by the nu meral 15 and is subjected to t e combinedaction of heat and pressure to obtain an efiicient and permanent bondbetween the laminations. This invention is not restricted to any methodof treating the sandwich while in the press and any-desired range ofpressures and temperatures can be used to give the desired results. 7

In Fig. 4 is illustrated a so-called bulletproof type of glasscomprising three sheets of glass and two sheets of non-brittle material.To rotect the bond between the laminations 0 the sheet 16, a seal 17 isused. In Fig. 5-regular non-shatterable glass compris in two'sheets oflass and a sheet of nonbrittle material is s own.

One of the bi problems in the production of laminated g ass is to obtainan efiicient bond between the laminations and to so obtain the bond thatthe finished sheet will not subsequently develop so-called after-cracksThe term after-cracks is used to designate a crack that appears in theglass sheets after the sheet has been formed.v Such cracks do not appearduring the pressin operation but on the other hand appear su sequent tothe removal of the sheet from the press. Aftercracks appear at varioustimes after the sheet has been formed, in fact the may show up a monthor so after the sheet as been. pressed.

Some laminated glass is produced by usin plate glass in its structurewhile other laminated (glass is formed by using ordinary ungroun andunpolished window glass. Although it would seem that after-cracks wouldnot appear in laminated glass formed from late g ass, nevertheless suchaftercracks do appear unless very exce tional care is exercised in themanufacture t ereof.

If the sticker members 12 are joined directly to the face of the glasssheets in the sandwich 10, and even thcugh cushion means are placedbetween the sandwich and the stickers 12 and the plates of the press 15,the stickers cause a strain to be introduced in the glass sheet. I havefound however, that these strains can be eliminated by placing at leastone of the compressible members 11 between the stickers and the glasssheets. Probably the thickness of the sticker is absorbed in thecompressible members 11 so that an uneven pressure is applied to thelaminated sandwic At any rate it has been found in actual practice thatthe arrangement of the stickers as above set forth gives much moresatisfactory results than when th stickers are applied directly to thesurface of the glass sheets. Further better results I are obtained inthe main when the stickers less prevented between the laminations. As

w them between said laminations, said stickshown in Fig. 2 at the leftthereof, the nonbrittle sheet extends beyond the edges of the glasssheets. This extension occurs when the non-brittle membrane flows duringthe joining of the laminations and'can be readily removed'by a sha knifeor the like.

It is to-be un erstood that the form of the invention herewith shown anddescribed is to be taken as the, preferred embodiment'of the same, andthat various changesin the 20.

shape, size and arrangement of parts may be resorted to withoutdeparting from the spirit of the invention or the scope of the subjoinedclaims. 7

I claim: v

1. The process of producing laminated glass, consisting in forming asandwich from the laminations to be joined, arranging a compressiblesheet on each side of the sandwich, applyin means adhering to the twocompressible s eets to prevent relative movement between the laminationscomprising the sandwich, then applying I additional compressible meanson each side of the sandwich, and then subjecting the entire assembly tothe action of pressureto obtain a bond between the laminations.

2. The rocess of producing laminated glass, consisting in forming asandwich from the laminations to (be joined, arranging a compressiblemember on each side of the sandwich, applying stickers at the edges ofthe sandwich and compressible members to prevent slip age between thelaminations, and then a p ying pressure to the assembly thus forme toobtain a bond between the laminations.

3. The rocess of producing laminated glass, consisting in formin asandwich from the laminations to be joine arran 'ng a compressiblemember on each side 0 the sandwich, applying stickers at the edges ofthe sandwich and compressible members to revent slippage between thelaminations, t en arran ing additional compressible members on eac sideof the assembly thus formed, and then applying pressure to the entireassembly to obtain a bond between the laminations.

a I The process of producing laminated glass, consisting in forming asandwich from the laminations to be joined, arranging a sheet ofcompressible material on each side of the sandwich, said sheets ofcompressible material being of identical size with the sandwich, aplying stickers at the corners of -i the san wich and overlapping thestickers over the compressible members, then arrangin additional comressible members on each si e of the sandwic and pressing the assemblythus formed to unite the laminations of said sandwich.

. 5. The rocess of producing laminated glass, consisting in forming asandwich from the laminations to be joined, and arranging stickersthereon to prevent relative moveers being arranged in a manner that theyhave substantially line contact only with the edges of the sandwich.

6. The rocess of producing laminated lass, consisting in formin asandwich from t e laminations to be j oine arranging a compressiblesheet on each side of the sandwich, applying means adhering to the twocompressible sheets to prevent relative movement between the laminationscomprising the sandwich, and then applyin pressure to the assembly thusformed to o tain a bond between the laminations.

7. The process of producing laminated glass, consisting in formin asandwich from the laminations to be joined, arranging a compressiblemember on each side of the sandwich, applying stickers thereon toprevent relative movement between the laminations, said stickers beingarranged in a manner that they have substantially line contact only withthe edges of the sandwich, and then pressing the assembly thus formed tounite the laminations of said sandwich Signed at Toledo, in the countyof Lucas and State of Ohio, this 29th day of June,

WILLARD C. MCDANUEL.

